brake light CHRYSLER VOYAGER 2005 Owner's Manual

PROPORTIONING VALVE
DESCRIPTION - PROPORTIONING VALVE
(HEIGHT SENSING)
NOTE: Only vehicles without antilock brakes (ABS)
have a proportioning valve. Vehicles with ABS uti-
lize electronic brake distribution which is controlled
through the ABS integrated control unit.
Vehicles not equipped with ABS use a height sens-
ing proportioning valve. It is mounted to the body of
the vehicle above the rear axle (Fig. 80). It has an
actuator lever that attaches to the rear axle and
moves with the axle to help the valve sense the vehi-
cle height.
CAUTION: The height sensing proportioning valve
is not adjustable. No attempt should be made to
adjust it. It is replaced as a complete assembly.
CAUTION: The use of after-market load leveling or
load capacity increasing devices on this vehicle are
prohibited. Using air shock absorbers or helper
springs on this vehicle will cause the height sens-
ing proportioning valve to inappropriately reduce
the hydraulic pressure to the rear brakes. This inap-
propriate reduction in hydraulic pressure potentially
could result in increased stopping distance of the
vehicle.
OPERATION - PROPORTIONING VALVE
(HEIGHT SENSING)
Vehicles not equipped with ABS use a height sens-
ing proportioning valve.
The height sensing proportioning valve operates
similarly to a standard proportioning valve in the fol-
lowing way. As hydraulic pressure is applied to the
valve, full input hydraulic pressure is supplied to the
rear brakes up to a certain pressure point, called the
split point. Beyond the split point, the proportioning
valve reduces the amount of hydraulic pressure to
the rear brakes according to a given ratio. Thus, on
light brake applications, approximately equal
hydraulic pressure will be transmitted to both the
front and rear brakes. Upon heavier brake applica-
tions, the hydraulic pressure transmitted to the rear
brakes will be lower than the front brakes. This will
prevent premature rear wheel lockup and skid.
Here is how the height sensing proportioning valve
differs from a standard proportioning valve. As the
height of the rear suspension changes, the height
sensing portion of the proportioning valve changes
the split point of the proportioning valve. When the
height of the rear suspension is low, the proportion-
ing valve interprets this as extra load and the split
point of the proportioning valve is raised to a higher
pressure to allow for more rear braking. When the
height of the rear suspension is high, the proportion-
ing valve interprets this as a light load and the split
point of the proportioning valve is lowered to a lower
pressure and rear braking is reduced.
The height sensing proportioning valve regulates
the pressure by sensing the load condition of the
vehicle through the movement of the proportioning
valve actuator lever (Fig. 80). As the position of the
rear axle changes, depending on the load the vehicle
is carrying, the movement is transferred to the pro-
portioning valve. The proportioning valve adjusts the
hydraulic pressure accordingly.
The height sensing proportioning valve allows the
brake system to maintain the optimal front to rear
brake balance regardless of the vehicle load condi-
tion. Under a light load condition, hydraulic pressure
to the rear brakes is minimized. As the rear load con-
dition increases, so does the hydraulic pressure to
the rear brakes.
Fig. 80 HEIGHT SENSING PROPORTIONING VALVE
1 - PROPORTIONING VALVE
2 - ACTUATOR LEVER
3 - AXLE BRACKET
4 - REAR AXLE
RSBRAKES - BASE5-53

BRAKING SURFACE INSPECTION
Light braking surface scoring and wear is accept-
able. If heavy scoring or warping is evident, the rotor
must be refaced or replaced. (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTORS - STAN-
DARD PROCEDURE).
Excessive wear and scoring of the rotor can cause
improper lining contact on the rotor's braking sur-
face. If the ridges on the rotor are not removed before
new brake shoes are installed, improper wear of the
shoes will result.
If a vehicle has not been driven for a period of
time, the rotor's braking surface will rust in the
areas not covered by the brake shoes at that time.
Once the vehicle is driven, noise and chatter from
the disc brakes can result when the brakes are
applied.
Some discoloration or wear of the rotor surface is
normal and does not require resurfacing when lin-
ings are replaced. If cracks or burned spots are evi-
dent, the rotor must be replaced.
ROTOR MINIMUM THICKNESS
Measure rotor thickness at the center of the brake
shoe contact surface. Replace the rotor if it is worn
below minimum thickness or if machining the rotor
will cause its thickness to fall below specifications.
CAUTION: Do not machine the rotor if it will cause
the rotor to fall below minimum thickness.
Minimum thickness specifications are cast on the
rotor's unmachined surface (Fig. 82). Limits can also
be found in this section's specification table. (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/ROTOR -
SPECIFICATIONS)
ROTOR THICKNESS VARIATION
Thickness variation in a rotor's braking surface
can result in pedal pulsation, chatter and surge. This
can be caused by excessive runout in the rotor or the
hub.
Rotor thickness variation measurements should be
made in conjunction with measuring runout. Mea-
sure thickness of the brake rotor at 12 equal points
around the rotor braking surface with a micrometer
at a radius approximately 25 mm (1 inch) from edge
of rotor (Fig. 83). If thickness measurements vary
beyond the specification listed in the specifaction
table (Refer to 5 - BRAKES/HYDRAULIC/MECHAN-
ICAL/ROTOR - SPECIFICATIONS), the rotor should
be refaced or replaced. (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS - STANDARD
PROCEDURE).
Fig. 82 Minimum Brake Rotor Thickness Markings
(Typical)
1 - ROTOR MINIMUM THICKNESS MARKING
2 - ROTOR
Fig. 83 Checking Rotor For Thickness
1 - CALIPER
5 - 56 BRAKES - BASERS
ROTOR (Continued)

CAUTION: Corrosion may occur between the hub/
bearing and the axle flange. If this occurs, the hub/
bearing will be difficult to remove from the axle and
disc brake caliper adapter. If the hub/bearing will
not come out by pulling on it by hand, don't not
pound on it with a hammer. Pounding on the hub/
bearing will damage it. To remove a hub/bearing
that is corroded in place, lightly tap the disc brake
caliper adapter using a soft-face hammer. This will
remove both the caliper adapter and hub/bearing
together from the axle. With a helper supporting the
caliper adapter in his hands, position Remover,
Special Tool 8214-1, on the cast housing of hub/
bearing (Fig. 141). Do not position the special tool
on the inner race of hub/bearing. Lightly strike the
Remover with a hammer to remove the hub/bearing
from the caliper adapter.
(20) Remove the adapter from the rear axle.
(21) Mount the adapter in a vise using the anchor
boss for the park brake cable (Fig. 142).
(22) Remove the lower return spring (Fig. 143)
from the leading and trailing park brake shoes.
Fig. 141 Hub/Bearing Removal From Caliper Adapter
1 - SPECIAL TOOL 8214-1
2 - PARK BRAKE CABLE
3 - DISC BRAKE CALIPER ADAPTER
4 - HUB/BEARING
Fig. 142 Adapter Mounted In Vise
1 - ADAPTER
2 - PARK BRAKE CABLE BOSS
3 - VISE
4 - PARK BRAKE BRAKE SHOES
Fig. 143 Lower Return Spring
1 - ADAPTER
2 - LEADING PARK BRAKE SHOE
3 - RETURN SPRING
4 - TRAILING PARK BRAKE SHOE
5 - 82 BRAKES - BASERS
SHOES - PARKING BRAKE (Continued)

DESCRIPTION - ELECTRONIC VARIABLE
BRAKE PROPORTIONING
Vehicles equipped with ABS use electronic variable
brake proportioning (EVBP) to balance front-to-rear
braking. The EVBP is used in place of a rear propor-
tioning valve. The EVBP system uses the ABS system
to control the slip of the rear wheels in partial brak-
ing range. The braking force of the rear wheels is con-
trolled electronically by using the inlet and outlet
valves located in the integrated control unit (ICU).
EVBP activation is invisible to the customer since
there is no pump motor noise or brake pedal feedback.
DESCRIPTION - TRACTION CONTROL SYSTEM
Traction control reduces wheel slip and maintains
traction at the driving wheels at speeds below 56
km/h (35 mph) when road surfaces are slippery. The
traction control system reduces wheel slip by braking
the wheel that is losing traction.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves are
included on vehicles with traction control. These
valves are located inside the HCU and cannot be ser-
viced separately from the HCU.
TRACTION CONTROL LAMP
The traction control function lamp is located in the
transmission range indicator display of the instru-
ment cluster, displaying TRAC, TRAC OFF or nei-
ther depending on system mode.
The TRAC OFF lamp is controlled by a Traction
Control Off switch that is a momentary contact type
switch. The Traction Control Off switch is located on
the steering column upper shroud.
OPERATION
OPERATION - ANTILOCK BRAKE SYSTEM
There are a few performance characteristics of the
Mark 20e Antilock Brake System that may at first
seem abnormal, but in fact are normal. These char-
acteristics are described below.
NORMAL BRAKING
Under normal braking conditions, the ABS func-
tions the same as a standard base brake system with
a diagonally split master cylinder and conventional
vacuum assist.
ABS BRAKING
ABS operation is available at all vehicle speeds above
3±5 mph. If a wheel locking tendency is detected during
a brake application, the brake system enters the ABS
mode. During ABS braking, hydraulic pressure in thefour wheel circuits is modulated to prevent any wheel
from locking. Each wheel circuit is designed with a set of
electric solenoids to allow modulation, although for vehi-
cle stability, both rear wheel solenoids receive the same
electrical signal. Wheel lockup may be perceived at the
very end of an ABS stop and is considered normal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into three control channels.
During antilock operation of the vehicle's brake sys-
tem, the front wheels are controlled independently
and are on two separate control channels, and the
rear wheels of the vehicle are controlled together.
The system can build and release pressure at each
wheel, depending on signals generated by the wheel
speed sensors (WSS) at each wheel and received at
the controller antilock brake (CAB).
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping, or groaning noises heard by the
driver. This is normal and is due to pressurized fluid
being transferred between the master cylinder and
the brakes. If ABS operation occurs during hard
braking, some pulsation may be felt in the vehicle
body due to fore and aft movement of the suspension
as brake pressures are modulated.
At the end of an ABS stop, ABS is turned off when
the vehicle is slowed to a speed of 3±4 mph. There may
be a slight brake pedal drop anytime that the ABS is
deactivated, such as at the end of the stop when the
vehicle speed is less than 3 mph or during an ABS stop
where ABS is no longer required. These conditions exist
when a vehicle is being stopped on a road surface with
patches of ice, loose gravel, or sand on it. Also, stopping
a vehicle on a bumpy road surface activates ABS
because of the wheel hop caused by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lockup, some wheel slip is desired in order to achieve
optimum braking performance. Wheel slip is defined
as follows: 0 percent slip means the wheel is rolling
freely and 100 percent slip means the wheel is fully
locked. During brake pressure modulation, wheel slip
is allowed to reach up to 25±30 percent. This means
that the wheel rolling velocity is 25±30 percent less
than that of a free rolling wheel at a given vehicle
speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lockup.
Complete wheel lockup normally leaves black tire
marks on dry pavement. The ABS will not leave dark
black tire marks since the wheel never reaches a
fully locked condition. However, tire marks may be
noticeable as light patched marks.
5 - 88 BRAKES - ABSRS
BRAKES - ABS (Continued)

START-UP CYCLE
When the ignition is turned on, a popping sound
and a slight brake pedal movement may be noticed.
The ABS warning lamp will also be on for up to 5
seconds after the ignition is turned on. When the
vehicle is first driven off, a humming may be heard
or felt by the driver at approximately 20±40 kph
(12±25 mph). All of these conditions are a normal
function of ABS as the system is performing a diag-
nosis check.
PREMATURE ABS CYCLING
Symptoms of premature ABS cycling include: click-
ing sounds from the solenoid valves; pump/motor
running; and pulsations in the brake pedal. Prema-
ture ABS cycling can occur at any braking rate of the
vehicle and on any type of road surface. Neither the
red BRAKE warning lamp, nor the amber ABS warn-
ing lamp, illuminate and no fault codes are stored in
the CAB.
Premature ABS cycling is a condition that needs to
be correctly assessed when diagnosing problems with
the antilock brake system. It may be necessary to use
a DRB scan tool to detect and verify premature ABS
cycling.
Check the following common causes when diagnos-
ing premature ABS cycling: damaged tone wheels;
incorrect tone wheels; damaged steering knuckle
wheel speed sensor mounting bosses; loose wheel
speed sensor mounting bolts; excessive tone wheel
runout; or an excessively large tone wheel-to-wheel
speed sensor air gap. Give special attention to these
components when diagnosing a vehicle exhibiting
premature ABS cycling.
After diagnosing the defective component, repair or
replace it as required. When the component repair or
replacement is completed, test drive the vehicle to
verify that premature ABS cycling has been cor-
rected.
OPERATION - ELECTRONIC VARIABLE BRAKE
PROPORTIONING
Upon entry into EVBP the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure, the outlet valve for
the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
hydraulic control unit (HCU) resulting in a drop in
fluid pressure to the rear brakes. In order to increase
the rear brake pressure, the outlet valve is switched
off and the inlet valve is pulsed. This increases the
pressure to the rear brakes. This back-and-forth pro-
cess will continue until the required slip difference is
obtained. At the end of EVBP braking (brakes
released) the fluid in the LPA drains back to themaster cylinder by switching on the outlet valve and
draining through the inlet valve check valve. At the
same time the inlet valve is switched on in case of
another brake application.
The EVBP will remain functional during many
ABS fault modes. If both the red BRAKE and amber
ABS warning indicators are illuminated, the EVBP
may not be functioning.
OPERATION - TRACTION CONTROL SYSTEM
The traction control module monitors wheel speed.
During acceleration, if the module detects front
(drive) wheel slip and the brakes are not applied, the
module enters traction control mode. Traction control
operation proceeds in the following order:
(1) Close the normally open isolation valves.
(2) Start the pump/motor and supply volume and
pressure to the front (drive) hydraulic circuit. (The
pump/motor runs continuously during traction con-
trol operation.)
(3) Open and close the build and decay valves to
maintain minimum wheel slip and maximum trac-
tion.
The cycling of the build and decay valves during
traction control is similar to that during antilock
braking, except the valves work to control wheel spin
by applying the brakes, whereas the ABS function is
to control wheel skid by releasing the brakes.
If the brakes are applied at anytime during a trac-
tion control cycle, the brake lamp switch triggers the
controller to switch off traction control.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves allow
pressure and volume to return to the master cylinder
reservoir when not consumed by the build and decay
valves. These valves are necessary because the
pump/motor supplies more volume than the system
requires.
TRACTION CONTROL LAMP
The traction control system is enabled at each igni-
tion cycle. It may be turned off by depressing the
Traction Control Off switch button when the ignition
is in the ON position. The traction control function
lamp (TRAC OFF) illuminates immediately upon
depressing the button.
The traction control function lamp illuminates dur-
ing a traction control cycle, displaying TRAC.
If the CAB calculates that the brake temperatures
are high, the traction control system becomes inoper-
ative until a time-out period has elapsed. During this
ªthermo-protection mode,º the traction control func-
tion lamp illuminates TRAC OFF; note that no trou-
ble code is registered.
RSBRAKES - ABS5-89
BRAKES - ABS (Continued)

CAUTION
The ABS uses an electronic control module, the
CAB. This module is designed to withstand normal
current draws associated with vehicle operation.
Care must be taken to avoid overloading the CAB
circuits.
CAUTION: In testing for open or short circuits, do
not ground or apply voltage to any of the circuits
unless instructed to do so for a diagnostic proce-
dure.
CAUTION: These circuits should only be tested
using a high impedance multi-meter or the DRBIIIT
scan tool as described in this section. Power
should never be removed or applied to any control
module with the ignition in the ON position. Before
removing or connecting battery cables, fuses, or
connectors, always turn the ignition to the OFF
position.
CAUTION: The CAB 24-way connector should never
be connected or disconnected with the ignition
switch in the ON position.
CAUTION: This vehicle utilizes active wheel speed
sensors. Do not apply voltage to wheel speed sen-
sors at any time.
CAUTION: Use only factory wiring harnesses. Do
not cut or splice wiring to the brake circuits. The
addition of aftermarket electrical equipment (car
phone, radar detector, citizen band radio, trailer
lighting, trailer brakes, etc.) on a vehicle equipped
with antilock brakes may affect the function of the
antilock brake system.
CAUTION: When performing any service procedure
on a vehicle equipped with ABS, do not apply a
12-volt power source to the ground circuit of the
pump motor in the HCU. Doing this will damage the
pump motor and will require replacement of the
entire HCU.
CAUTION: An attempt to remove or disconnect cer-
tain system components may result in improper
system operation. Only those components with
approved removal and installation procedures in
this manual should be serviced.
CAUTION: If welding work is to be performed on the
vehicle using an electric arc welder, the CAB con-nector should be disconnected during the welding
operation.
CAUTION: Many components of the ABS System
are not serviceable and must be replaced as an
assembly. Do not disassemble any component
which is not designed to be serviced.
CAUTION: Only the recommended jacking or hoist-
ing positions for this vehicle are to be used when-
ever it is necessary to lift a vehicle. Failure to raise
a vehicle from the recommended locations could
result in lifting a vehicle by the hydraulic control
unit mounting bracket. Lifting a vehicle by the
hydraulic control unit mounting bracket will result
in damage to the mounting bracket and the hydrau-
lic control unit.
CAUTION: Brake fluid will damage painted surfaces.
If brake fluid is spilled on any painted surface,
wash off with water immediately.
STANDARD PROCEDURE - ANTILOCK BRAKE
SYSTEM BLEEDING
The base brake's hydraulic system must be bled
anytime air enters the hydraulic system. The ABS
though, particularly the ICU (HCU), should only be
bled when the HCU is replaced or removed from the
vehicle. The ABS must always be bled anytime it is
suspected that the HCU has ingested air. Under
most circumstances that require the bleeding of the
brakes hydraulic system, only the base brake
hydraulic system needs to be bled.
It is important to note that excessive air in the
brake system will cause a soft or spongy feeling
brake pedal.
During the brake bleeding procedure, be sure the
brake fluid level remains close to the FULL level in
the master cylinder fluid reservoir. Check the fluid
level periodically during the bleeding procedure and
add DOT 3 brake fluid as required.
The ABS must be bled as two independent braking
systems. The non-ABS portion of the brake system
with ABS is to be bled the same as any non-ABS sys-
tem.
The ABS portion of the brake system must be bled
separately. Use the following procedure to properly
bleed the brake hydraulic system including the ABS.
BLEEDING
When bleeding the ABS system, the following
bleeding sequence must be followed to insure com-
plete and adequate bleeding.
5 - 90 BRAKES - ABSRS
BRAKES - ABS (Continued)

ENGINE
DIAGNOSIS AND TESTING - ENGINE COOLING
SYSTEM
Establish what driving condition caused the cooling
system complaint. The problem may be caused by an
abnormal load on the system such as the following:
prolonged idle, very high ambient temperature, slight
tail wind at idle, slow traffic speed, traffic jam, high
speed, steep grade.
DRIVING TECHNIQUES
To avoid overheating the cooling system:
(1) Idle with A/C off when temperature gauge is at
end of normal range.
(2) Do not increase engine speed for more air flow
and coolant flow because the electric motor fan sys-
tems are not responsive to engine RPM. The added
cooling from higher coolant flow rate is more than
offset by increased heat rejection (engine heat added
to coolant).
TRAILER TOWING
Consult the owner's manual under Trailer Towing
and do not exceed specified limits.
VISUAL INSPECTION
If the cooling system problem is not caused by a
driving condition, perform a visual inspection to
determine if there was a recent service or accident
repair, including the following:
²Loose/damaged water pump drive belt
²Incorrect cooling system refilling (trapped air or
low level)
²Brakes possibly dragging
²Damaged hoses
²Loose/damaged hose clamps
²Damaged/incorrect engine thermostat
²Damaged cooling fan motor, fan blade and fan
shroud
²Damaged head gasket
²Damaged water pump
²Damaged radiator
²Damaged coolant recovery system
²Damaged heater core
²Open/shorted electrical circuits
If the visual inspection reveals none of the above
as cause for a cooling system complaint, refer to the
following diagnostic charts.
COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR COOLANT.
TEMPERATURE GAUGE READING
MAY BE ABOVE NORMAL BUT
NOT HIGH. COOLANT LEVEL MAY
BE HIGH IN COOLANT RESERVE/
OVERFLOW TANK.1. Pressure relief valve in radiator
cap is defective, or was not
properly seated.1. Check condition of radiator cap
and cap seal. (Refer to 7 -
COOLING/ENGINE/RADIATOR
PRESSURE CAP - DIAGNOSIS
AND TESTING) Replace cap as
necessary.
2. Incorrect cap was installed. 2. Replace cap as necessary.
3. Incorrect coolant mixture. 3. Check concentration level of the
coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS
AND TESTING) Adjust the ethylene
glycol-to-water ratio as required.
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE IS
READING HIGH OR HOT.1. Coolant leaks in radiator, cooling
system hoses, water pump or
engine.1. Pressure test and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING)
7 - 14 ENGINERS

PARK ASSIST SYSTEM
The Park Assist System display activates an audi-
ble tone that changes from intermittent to continu-
ous as the final two Light Emitting Diodes (LED's)
are illuminated on one side or both sides of the dis-
play.
The system detection length from the rear of the
vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The system detec-
tion height from the ground is 0.2 meters to about
1.5 meters. The radio mutes when the system acti-
vates its audible tone.
When the driver selects Reverse the system scans
for objects behind the vehicle using four sensors
located in the rear bumper. A warning display above
the rear window provides both visible and audible
warnings indicating the range of the object.
The system is active only when the transmission
gear selector is in reverse for vehicle speeds less than
16 Km/h (10 mph). If the vehicle's Parking/Emer-
gency Brake is applied, the system is deactivated.
The display contains two sets of yellow and red
Light Emitting Diode's (LED's) that the driver can
see as they look over their shoulder while backing
up. Each side of the vehicle has its own warning
LED's. The system provides a visual warning by illu-
minating one or more yellow LED's as the vehicle
gets closer to the object. As the vehicle continues to
approach the object, one red LED is illuminated and
the system emits a series of short beeps. The tone
will remain constant and both red LED's are illumi-
nated once the vehicle is within 12 inches (30.5 cm)
of the object.
The system can be turned ON or OFF through the
Electronic Vehicle Information Center (EVIC) when
the vehicle is in PARK. If the park assist system is
turned OFF, a single chime will sound and the EVIC
will display the following message ªREAR PARK
ASSIST OFFº, when the vehicle is in reverse.
²Ensure that the rear bumper is free of dirt and
debris to keep the system operating properly.
²Jackhammers, large trucks, and other vibrations
could affect the performance of the system.
²Ensure that the parking brake is not applied.
If ªService Park Assist Systemº appears in the
EVIC after making sure the rear bumper is clean,
proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.
WARNING
On vehicles equipped with airbags, disable
the airbag system before attempting any steer-
ing wheel, steering column, or instrument
panel component diagnosis or service. Discon-
nect and isolate the battery negative (ground)
cable, then wait two minutes for the airbag sys-
tem capacitor to discharge before performing
further diagnosis or service. This is the only
sure way to disable the airbag system. Failure
to take the proper precautions could result in
accidental airbag deployment, personal injury,
or death.
DIAGNOSIS AND TESTING - CHIME SYSTEM
Refer to the proper Body Diagnostic Procedures
manual for complete Diagnosis and Testing of the
Chime System.
NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER'S SEAT BELT IS NOT BUCKLED.
(1) Using a DRB llltscan tool, actuate chime
(BCM actuates).
(2) Using a voltmeter, check for voltage:
(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
(3) Check drivers seat belt buckle switch input
(from Occupant Restraint Controller (ORC) for a
closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.
(4) Verify Programmable Communication Interface
(PCI) data bus communication between ORC and
BCM.
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)

²System diagnostics - diagnosis and error han-
dling (sensors, display, module).
²Data exchange over the Programmable Commu-
nication Interface (PCI) data bus.
OPERATION
The module has a number of functions:
²Supply voltage to the sensors and display.
²Disconnection of the display with bus idle and
over voltage Vmax.
²Triggering the sensors.
²Analyze echo delay times and calculate obstacle
distances.
²Bi-directional data communication to the display
for diagnosis.
²System diagnostics - diagnosis and error han-
dling (sensors, display, module).
²Data exchange over the Programmable Commu-
nication Interface (PCI) data bus.
The system detection length from the rear of the
vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The system detec-
tion height from the ground is 0.2 meters to about
1.5 meters. The radio mutes when the system acti-
vates its audible tone.When the driver selects Reverse, the system scans
for objects behind the vehicle using four sensors
located in the rear bumper. Objects can be detected
from up to 1.5 meters. A warning display above the
rear window provides both visible and audible warn-
ings indicating the range of the object.
The system is active only when the vehicle is in
reverse for vehicle speeds less than 16 Km/h (10
mph). If the vehicles Parking/Emergency Brake is
applied, the system is deactivated.
The display contains two sets of yellow and red
Light Emitting Diode's (LED's) that the driver can
see as they look over their shoulder while backing
up. Each side of the vehicle has its own warning
LED's. The system provides a visual warning by illu-
minating one or more yellow LED's as the vehicle
gets closer to the object. As the vehicle continues to
approaches the object, one red LED is illuminated
and the system emits a series of short beeps. The
tone will remain constant and both red LED's are
illuminated once the vehicle is within 12 inches (30.5
cm) of the object.
The system can be turned ON or OFF through the
Electronic Vehicle Information Center (EVIC) when
the vehicle is in PARK. If the park assist system is
turned OFF, a single chime will sound and the EVIC
will display the following message ªREAR PARK
ASSIST OFFº, when the vehicle is in reverse.
²Ensure that the rear bumper is free of dirt and
debris to keep the system operating properly.
²Jackhammers, large trucks, and other vibrations
could affect the performance of the system.
²Ensure that the parking brake is not applied.
If ªService Park Assist Systemº appears in the
EVIC after making sure the rear bumper is clean,
proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.
To diagnose the Park Assist Module, use a scan
tool and the appropriate body diagnostic information.
REMOVAL
(1) Open hood.
(2)
Disconnect and isolate the battery negative cable.
(3) Remove the left quarter trim panel (Refer to 23
- BODY/INTERIOR/QUARTER TRIM PANEL -
REMOVAL).
Fig. 3 PARK ASSIST MODULE - LOCATION
1 - RETAINING SCREW J-CLIPS
2 - LEFT QUARTER PANEL/C-PILLAR
3 - MODULE RETAINING SCREWS
4 - PARK ASSIST MODULE
RSCHIME/BUZZER8B-5
PARK ASSIST MODULE (Continued)

The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus.
OPERATION
The Body Control Module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the BCM is interfaced to the
vehicle's serial bus communications network, referred
to as the Programmable Communications Interface
(PCI) bus.
This network consists of the;
²Powertrain Control Module (PCM)
²Transmission Control Module (TCM)
²Mechanical Instrument Cluster (MIC)
²Occupant Restraint Controller (ORC)
²Compass/Mini-Trip Computer (CMTC)
²Electronic Vehicle Information Center (EVIC)
²Controller Antilock Brake (CAB)
²HVAC Control Module
²Sliding Door Control Modules (driver and pas-
senger side doors)
²Power Liftgate Module (PLG)
²Audio system equipped with RAZ, RBU, RBK,
and RBB radios.
²Sentry Key Remote Entry Module (SKREEM).
²Side Impact Airbag Control Module (SIACM)²Memory Seat Module (MSM)
²Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is
supplied to the module.
The BCM provides the following features:
²Power Door Locks
²Automatic Door Locks
²Battery Protection - The BCM will automatically
turn off all exterior lamps after 3 minutes, and all
interior lamps after 15 minutes after the ignition is
turned off, if they are not turned off by the driver.
²Chime Control
²Compass/Mini-Trip support.
²Interior Lighting (Courtesy/Reading Lamps)
²BCM Diagnostic Reporting
²Electronic Liftgate Release (with Power Door
Locks)
²Exterior Lighting
²Headlamp Time Delay (with/without Automatic
Headlamps)
²Illuminated Entry
²Fade to Off Interior Lamps - This feature dims
the interior lighting (courtesy lamps) gradually if the
BCM does not receive any new inputs that would
cause the interior lamps to remain on.
²Pulse Width Modulated Instrument Panel Dim-
ming
²Door Lock Inhibit - This feature disables the
door lock functions if the key is in the ignition and
either front door is ajar. Pressing the Remote Keyless
Entry (RKE) lock/unlock button under these condi-
tions result in normal lock/unlock activation.
The BCM has the ability to LEARN additional fea-
tures in the vehicle, provided the appropriate switch
input and PCI data bus messages are received. Refer
to the LEARNED FEATURES table.
LEARNED FEATURES
FEATURE LEARNING KEY
REAR WIPER CONTROL ON HVAC CONTROL ON
INSTRUMENT PANELPCI BUS MESSAGE RECEIVED FROM HVAC
CONTROL
AUTOMATIC HEADLAMPS PCI MESSAGE FROM OVERHEAD OR HEADLAMP
SWITCH POSITION (AUTO)
REMOTE KEYLESS ENTRY SKREEM MESSAGE RECEIVED FROM MODULE
FRONT FOG LAMPS HEADLAMP SWITCH POSITION (PARK W/FRONT
FOG LAMPS)
POWER SLIDING DOOR PCI IFR RECEIVED FROM MODULE
THE BCM HAS FOUR SWITCH INPUTS FOR THE POWER SLIDING DOOR FEATURE; LOCATED IN THE
OVERHEAD CONSOLE ARE THE LEFT AND RIGHT SIDE SLIDING DOOR SWITCHES TO ACTIVATE EITHER
OR BOTH SLIDING DOORS UNDER THE PROPER CONDITIONS. ALSO ARE B-PILLAR SWITCHES LOCATED
ON THE LEFT AND RIGHT B-PILLAR POSTS.
POWER LIFTGATE PCI IFR RECEIVED FROM MODULE
RSELECTRONIC CONTROL MODULES8E-3
BODY CONTROL MODULE (Continued)